1. Field of the Invention
This invention generally relates to a pointing device for controlling the positioning, movement and operation of a cursor on a display screen associated with a computer and, more particularly, to an integrated pointing device that is mountable to a printed circuit board.
2. Description of the Related Art
Various devices are well known for controlling cursor movement over a display screen associated with a computer. Depending on the type of computer program in operation, the position of the cursor on a display screen may indicate a choice of computer commands on a menu associated with the computer program displayed on the display screen menu. One such device is a "mouse" which has a ball mounted to its underside for contacting a horizontal surface and rolling therealong when manipulated by a computer operator. The X- and Y-axis components of movement are sensed and transmitted through a connecting cable to a serial input port of the computer. This signal to the computer is varied by the amount and direction of mouse ball movement, and causes a corresponding movement of the cursor on the display screen. Typically a pair of "mouse" or "click" buttons are located on the top of the mouse at the forward end thereof. The buttons permit a computer operator to enter a selection or other command to the computer (the command typically being shown by the position of the cursor on the displayed menu) upon pressing one or the other or both buttons, depending upon the software associated with the mouse. Such a device, which is separate from the computer console and keyboard, requires a connection to a computer port and a flat, horizontal supporting surface for proper operation. Furthermore, the computer operator must completely remove one hand from the computer keyboard in order to move the mouse and thus the cursor on the display screen and then reposition the hand again over the keys of the keyboard to resume data entry.
Another cursor controlling and signaling mechanism is a "joystick" which, like the mouse, is completely separated from the computer console and keyboard. The joystick is typically an elongated, upright stick that extends upwardly from a base connected to the computer console by means of an electrical cable. The joystick is operated by tilting the upright stick in various directions to cause the cursor or other display element to move on the display screen in a direction and usually at a speed corresponding to the direction and pressure exerted on the stick by the computer operator. The operation of a joystick, however, frequently requires that both hands be moved from the computer keyboard, with one hand holding the base and the other hand manipulating the joystick. A "click" button is usually located on the joystick. Although a mouse or joystick can be used with a portable "laptop" or "notebook" sized computer, such devices are cumbersome, since they must be carried separately and connected to the computer before use. Moreover, such devices are not suitable for operation during travel.
A "trackball" is still another type of known cursor controlling device. This device, which in essence is an inverted mouse, includes a rotatable ball mounted within a housing. The ball is rotated by a finger, thumb or palm of the computer operator, and the X- and Y-components of movement are sensed and input into the computer with corresponding movement of the cursor across the display screen. "Mouse" or "click" buttons are usually located on the trackball housing, although with some models a selection signal is input by pressing the "enter" key on the standard keyboard. This type of pointing device has been somewhat useful with portable computers because it can be temporarily affixed to one side of the computer case for manipulation by one hand of the computer operator. However, although trackball devices can be removably mounted to the computer case, they still required attachment before use and removal after use and repositioning of the computer operator's hand during use. It is also noted that some trackball's are built into the computer keyboard. Nonetheless, these trackball's required a separate set of "click" buttons for selection of items on the display monitor.
Manufacturers of portable laptop computers, recognizing the need for placing the cursor controlling device in a permanent and more convenient location, have more recently installed a small, stubby button-like joystick at a central position on the computer keyboard, such as at the juncture of the "g," "h" and "b" keys of the standard "QWERTY" keyboard. The button-like joystick, also known as a pointing stick, is sensitive to lateral pressure, the amount and direction of which are sensed and input into the computer to cause movement of the cursor, with the speed and direction of cursor movement corresponding to the amount and direction of pressure on the pointing stick. In order to select items on the display screen, upwardly extending "mouse" or "click" buttons must be provided somewhere on the computer, typically at a location remote from the pointing stick. This, as with the previously described cursor control devices, is disadvantageous since the hand and fingers of the computer operator must be repositioned in order to actuate the buttons and then be moved again to the proper keyboard position for typing.
Another disadvantage associated with a keyboard-mounted pointing stick is that a communication cable must extend from the pointing stick to a circuit board that provides a power source, amplifiers, and calibration electronics for the pointing stick. The circuit board is spaced from the pointing stick and care must be exercised when installing the cable therebetween. Moreover, the materials that make up the cable, its process of forming and method of attachment to the pointing stick contribute to increased overall cost of the pointing stick.
Examples of patents related to the present invention are as follows, wherein each patent is herein incorporated by reference for related and supporting teachings:
U.S. Pat. No. Re. 35,016 discloses a three-axis force measurement stylus.
U.S. Pat. No. 5,754,167 discloses a coordinate input device for a computer keyboard, wherein signals from the input device are transmitted to a separate control section by way of a flexible cable.
U.S. Pat. No. 5,754,166 discloses a coordinate input device for a computer keyboard. The input device has a pointing stick with heat-shrinkable tubing installed therearound for affixing strain sensors on the side surfaces of the pointing stick.
U.S. Pat. No. 5,712,660 discloses a cursor control stick for mounting in a computer keyboard. The control stick has a slidable plunger for generating Z-axis signals for selection of an item on a computer screen.
U.S. Pat. No. 5,659,334 discloses a pointing stick with a concave lower surface that rides on a force-sensing resistor network for sensing direction of pointing stick tilt.
U.S. Pat. No. 5,489,900 discloses a force sensitive transducer for use in a computer keyboard.
U.S. Pat. No. 5,325,081 discloses a supported strain gauge and joy stick assembly and method of making.
U.S. Pat. No. 5,263,375 discloses a contact detector using resistance elements and its application.
U.S. Pat. No. 4,905,523 discloses a force detector and moment detector using resistance elements.
U.S. Pat. No. 4,876,524 discloses an isometric control device or the like of the type having an elastic beam and strain gauges attached to the surface of the beam characterized by at least a first group of three strain gages each having an operative axis thereof inclined with a single predetermined angle with respect to the main axis of the beam, and the strain gauges disposed at a first predetermined level along the beam.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicants' acknowledged duty of candor in disclosing information that may be pertinent in the examination of this application. It is expressly stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicants' claimed invention.